Problems with ipxe and pxe-/syslinux

[zeox]

Hello,
I like to boot my old Asus Laptop via ipxe. When I directly load the ipxe file via my dhcp Server all works fine. I have created the ipxe file via "make bin/undionly.kpxe".
Following vendor show up 9508:0070

Now I like to boot pxelinux first and than load my custom ipxe lkrn-file.
My pxelinux entry is this:
label ipxe
menu label ^Load iPXE
kernel pxe/undionly.lkrn

The ipxe-file is created via "make bin/undionly.lkrn".
I can load it and ipxe starts but no network card will detect! In a Virtualbox all works fine.